Physicists have long ago proposed the existence of dark matter and dark energy. But as of now, there is very little that is known about them. While scientists have successfully identified and studied 17 different particles of visible physics including electrons, photons and the most recently discovered Higgs boson, the same cannot be said about the particles of the hidden physical world of dark matter.

Skeptical physicists have even discussed their views of non-existence of any such hidden universe and particles. However, the fact that the "standard model" of visible physics fails to explain the concept behind "gravity or the rate of expansion of the universe" emphasizes on the existence of hypothetical forces of dark energy.

Though it has been proposed that dark matter and energy together make up 95 percent of the total universe, little is known about its consisting particles. Some physicists have put forward a theory that our incompetence in studying dark matter and energy is not because they do not exist but rather due to the fact that scientists were not aware of the existence of the portals between visible and dark universe. Hypothetically, these portals mediate interactions between the regular particles and the dark particles, Science Alert reported.

The existence of such hypothetical portals was proposed by some scientists from the Center for Theoretical Physics of the Universe, Institute for Basic Science (IBS). The scientists published article in Physical Review Letters that elucidated the possible connection between the two worlds and how its understanding could help in unraveling the hidden mysteries of cosmology and astrophysics.

According to Science Daily, the two particles of the dark sector can most likely be explained as axions or dark photons. Both are extremely light particles, which according to the scientists, help in solving many critical problems of the standard model. The difference is, while the photons are known to be coupled with electromagnetic charge, the dark photons may be coupled with dark charge.

The proposal of existence of portals to the dark forces, otherwise referred to as the "dark axion" portals, is based on the recently observed "new heavy quarks."

Physicists are of the opinion that these quarks may be having dark charges that can couple with the dark photons, so that the axion and photon can interact with the dark photon. Further analysis of these hypothetical portals may open new "portals" towards understanding hitherto unexplained cosmological secrets.